In applications of adhesives, exterior paints, hard coats, antireflection layers, and so on in which an organic material or inorganic material is blended, investigations for improving the scar resistance, the strength of a hardened material, the adhesion to other raw material to be contacted, and so on have been made.
Above all, in a combination with an organic material of a polymerization hardening system, a polymerization group-containing alkoxysilane and/or a hydrolyzate thereof is being watched. For example, JP-A-9-169847 proposes a joint use of a specified polyalkoxypolysiloxane and a polymerizable silane coupling agent.
On the other hand, in general, in display devices such as a cathode ray tube display device (CRT), a plasma display (PDP), an electroluminescence display (ELD), and a liquid crystal display device (LCD), for the purpose of preventing a lowering of contrast or reflection of an image due to the reflection of external light, an antireflection film is arranged on the outermost surface of a display device so as to reduce a reflectance by using a principle of optical interference.
Such an antireflection film can be prepared by forming a high refractive index layer such as a hard coat layer on a support and further forming a low refractive index layer having an appropriate thickness thereon. In order to realize a low reflectance, it is desired to use a material having a low refractive index as far as possible for the low refractive index layer. Also, since the antireflection film is used for the outermost surface of a display device, in many cases, the low refractive index layer which becomes an uppermost layer is required to have high scar resistance. However, in the low refractive index layer which is a thin film having a thickness of about 100 nm, in order to realize high scar resistance, the film itself must have strength by itself and adhesion to a lower layer.
In order to decrease the refractive index of a layer, there are measures such as (1) introduction of a fluorine atom and (2) decrease of density (introduction of voids). However, in all of these measures, the film strength or adhesion is deteriorated so that the scar resistance tends to be lowered. Thus, it was a difficult problem to make low refractive index and high scar resistance compatible with each other.
For example, JP-A-11-189621, JP-A-11-228631 and JP-A-2000-313709 describe a measure for lowering a friction coefficient of a film surface to improve the scar resistance by introducing a polysiloxane structure in a fluorine-containing polymer.